linux/fs, branch v6.8

Merge tag 'erofs-for-6.8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs

2024-03-07T17:31:47Z

Pull erofs fixes from Gao Xiang: "The main one is a KMSAN fix which addresses an issue introduced in this cycle so it'd be much better to fix before releasing, and the remaining one fixes VMA alignment for THP. Summary: - Fix a KMSAN uninit-value issue triggered by a crafted image - Fix VMA alignment for memory mapped files on THP" * tag 'erofs-for-6.8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs: erofs: apply proper VMA alignment for memory mapped files on THP erofs: fix uninitialized page cache reported by KMSAN

erofs: apply proper VMA alignment for memory mapped files on THP

2024-03-07T02:21:10Z

There are mainly two reasons that thp_get_unmapped_area() should be used for EROFS as other filesystems: - It's needed to enable PMD mappings as a FSDAX filesystem, see commit 74d2fad1334d ("thp, dax: add thp_get_unmapped_area for pmd mappings"); - It's useful together with large folios and CONFIG_READ_ONLY_THP_FOR_FS which enable THPs for mmapped files (e.g. shared libraries) even without FSDAX. See commit 1854bc6e2420 ("mm/readahead: Align file mappings for non-DAX"). Fixes: 06252e9ce05b ("erofs: dax support for non-tailpacking regular file") Fixes: ce529cc25b18 ("erofs: enable large folios for iomap mode") Fixes: e6687b89225e ("erofs: enable large folios for fscache mode") Reviewed-by: Jingbo Xu Reviewed-by: Chao Yu Signed-off-by: Gao Xiang Link: https://lore.kernel.org/r/20240306053138.2240206-1-hsiangkao@linux.alibaba.com

erofs: fix uninitialized page cache reported by KMSAN

2024-03-07T02:21:00Z

syzbot reports a KMSAN reproducer [1] which generates a crafted filesystem image and causes IMA to read uninitialized page cache. Later, (rq->outputsize > rq->inputsize) will be formally supported after either large uncompressed pclusters (> block size) or big lclusters are landed. However, currently there is no way to generate such filesystems by using mkfs.erofs. Thus, let's mark this condition as unsupported for now. [1] https://lore.kernel.org/r/0000000000002be12a0611ca7ff8@google.com Reported-and-tested-by: syzbot+7bc44a489f0ef0670bd5@syzkaller.appspotmail.com Fixes: 1ca01520148a ("erofs: refine z_erofs_transform_plain() for sub-page block support") Reviewed-by: Sandeep Dhavale Reviewed-by: Yue Hu Reviewed-by: Chao Yu Signed-off-by: Gao Xiang Link: https://lore.kernel.org/r/20240304035339.425857-1-hsiangkao@linux.alibaba.com

iov_iter: get rid of 'copy_mc' flag

2024-03-06T09:52:12Z

This flag is only set by one single user: the magical core dumping code that looks up user pages one by one, and then writes them out using their kernel addresses (by using a BVEC_ITER). That actually ends up being a huge problem, because while we do use copy_mc_to_kernel() for this case and it is able to handle the possible machine checks involved, nothing else is really ready to handle the failures caused by the machine check. In particular, as reported by Tong Tiangen, we don't actually support fault_in_iov_iter_readable() on a machine check area. As a result, the usual logic for writing things to a file under a filesystem lock, which involves doing a copy with page faults disabled and then if that fails trying to fault pages in without holding the locks with fault_in_iov_iter_readable() does not work at all. We could decide to always just make the MC copy "succeed" (and filling the destination with zeroes), and that would then create a core dump file that just ignores any machine checks. But honestly, this single special case has been problematic before, and means that all the normal iov_iter code ends up slightly more complex and slower. See for example commit c9eec08bac96 ("iov_iter: Don't deal with iter->copy_mc in memcpy_from_iter_mc()") where David Howells re-organized the code just to avoid having to check the 'copy_mc' flags inside the inner iov_iter loops. So considering that we have exactly one user, and that one user is a non-critical special case that doesn't actually ever trigger in real life (Tong found this with manual error injection), the sane solution is to just decide that the onus on handling the machine check lines on that user instead. Ergo, do the copy_mc_to_kernel() in the core dump logic itself, copying the user data to a stable kernel page before writing it out. Fixes: f1982740f5e7 ("iov_iter: Convert iterate*() to inline funcs") Signed-off-by: Linus Torvalds Signed-off-by: Tong Tiangen Link: https://lore.kernel.org/r/20240305133336.3804360-1-tongtiangen@huawei.com Link: https://lore.kernel.org/all/4e80924d-9c85-f13a-722a-6a5d2b1c225a@huawei.com/ Tested-by: David Howells Reviewed-by: David Howells Reviewed-by: Jens Axboe Reported-by: Tong Tiangen Signed-off-by: Christian Brauner

fs/aio: Check IOCB_AIO_RW before the struct aio_kiocb conversion

2024-03-05T09:40:58Z

The first kiocb_set_cancel_fn() argument may point at a struct kiocb that is not embedded inside struct aio_kiocb. With the current code, depending on the compiler, the req->ki_ctx read happens either before the IOCB_AIO_RW test or after that test. Move the req->ki_ctx read such that it is guaranteed that the IOCB_AIO_RW test happens first. Reported-by: Eric Biggers Cc: Benjamin LaHaise Cc: Eric Biggers Cc: Christoph Hellwig Cc: Avi Kivity Cc: Sandeep Dhavale Cc: Jens Axboe Cc: Greg Kroah-Hartman Cc: Kent Overstreet Cc: stable@vger.kernel.org Fixes: b820de741ae4 ("fs/aio: Restrict kiocb_set_cancel_fn() to I/O submitted via libaio") Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20240304235715.3790858-1-bvanassche@acm.org Reviewed-by: Jens Axboe Reviewed-by: Eric Biggers Signed-off-by: Christian Brauner

Revert "fs/aio: Make io_cancel() generate completions again"

2024-03-05T09:00:57Z

Patch "fs/aio: Make io_cancel() generate completions again" is based on the assumption that calling kiocb->ki_cancel() does not complete R/W requests. This is incorrect: the two drivers that call kiocb_set_cancel_fn() callers set a cancellation function that calls usb_ep_dequeue(). According to its documentation, usb_ep_dequeue() calls the completion routine with status -ECONNRESET. Hence this revert. Cc: Benjamin LaHaise Cc: Eric Biggers Cc: Christoph Hellwig Cc: Avi Kivity Cc: Sandeep Dhavale Cc: Jens Axboe Cc: Greg Kroah-Hartman Cc: Kent Overstreet Cc: stable@vger.kernel.org Reported-by: syzbot+b91eb2ed18f599dd3c31@syzkaller.appspotmail.com Fixes: 54cbc058d86b ("fs/aio: Make io_cancel() generate completions again") Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20240304182945.3646109-1-bvanassche@acm.org Acked-by: Eric Biggers Signed-off-by: Christian Brauner

Merge tag 'xfs-6.8-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

2024-03-02T17:38:03Z

Pull xfs fix from Chandan Babu: "Drop experimental warning message when mounting an xfs filesystem on an fsdax device. We now consider xfs on fsdax to be stable" * tag 'xfs-6.8-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: drop experimental warning for FSDAX

Merge tag 'ceph-for-6.8-rc7' of https://github.com/ceph/ceph-client

2024-03-01T20:34:23Z

Pull ceph fix from Ilya Dryomov: "Catch up with mdsmap encoding rectification which ended up being necessary after all to enable cluster upgrades from problematic v18.2.0 and v18.2.1 releases" * tag 'ceph-for-6.8-rc7' of https://github.com/ceph/ceph-client: ceph: switch to corrected encoding of max_xattr_size in mdsmap

Merge tag 'for-6.8-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

2024-03-01T20:29:20Z

Pull btrfs fixes from David Sterba: - fix freeing allocated id for anon dev when snapshot creation fails - fiemap fixes: - followup for a recent deadlock fix, ranges that fiemap can access can still race with ordered extent completion - make sure fiemap with SYNC flag does not race with writes * tag 'for-6.8-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix double free of anonymous device after snapshot creation failure btrfs: ensure fiemap doesn't race with writes when FIEMAP_FLAG_SYNC is given btrfs: fix race between ordered extent completion and fiemap

Merge tag 'exfat-for-6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat

2024-03-01T20:22:30Z

Pull exfat fix from Namjae Jeon: - Fix ftruncate failure when allocating non-contiguous clusters * tag 'exfat-for-6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat: exfat: fix appending discontinuous clusters to empty file